Long-term growth and monitoring of the Eastern Hellbender (Cryptobranchus a. alleganiensis)
in Eastern West Virginia.
Thesis submitted to
the Graduate College of
Marshall University
In partial fulfillment of the
requirements for the degree of
Master of Science
Biological Sciences
by
Douglas Charles Horchler
Dr. Thomas K. Pauley, Committee Chair
Dr. Jefferey May, Committee Member
Dr. Dan Evans, Committee Member
Marshall University
May 2010
ABSTRACT
Long-term growth and monitoring of the Eastern Hellbender (Cryptobranchus a. alleganiensis)
in Eastern West Virginia.
Amphibian declines have been well documented, specifically in the last few decades. The
Hellbender, Cryptobranchus alleganiensis, one of North America’s largest salamander species,
has suffered dramatic declines throughout much of its range, with estimated declines of up to 77
percent recently documented in some populations. With diurnal and nocturnal searches and
mark-recapture techniques, I collected data on the status of Eastern Hellbender populations in
Eastern West Virginia. We re-sampled a study site on the West Fork of the Greenbrier River that
was first examined in 1998 by Jeff Humphries. Long-term growth and survivorship data were
collected and compared to 1998 data. Of the 29 hellbenders tagged within the West Fork site in
1998, 11 were recaptured in 2009. Eleven year mean growth of recaptured hellbenders is 3.38 cm
(range 0.6cm - 4.5 cm, n=11). A notable demography shift in both sex and size occurred from
1998 to 2009. In 1998 the population exhibited a 1.1:1 sex ratio, while the 2009 population
exhibited a 2.1:1 ratio. A marked shift in size class was noted, with the 2009 population
exhibiting shifts to larger size classes. However, evidence of reproduction was found in 2009
where it was lacking in 1998, potentially suggesting a viable population. The recapture data will
allow for a better understanding of the growth and age of large size classes of hellbenders.
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TABLE OF CONTENTS
ABSTRACT……………………………………………………………………………………ii
ACKNOWLEDGEMENTS…………………………………………………………………..iv
LIST OF TABLES…………………………………………………………………………….vii
LIST OF FIGURES……………………………………………………………………………viii
OVERVIEW OF FINDINGS…………………………………………………………………1
INTRODUCTION
Species Description………………………………………………………………………..2
Declines……………………………………………………………………………………3
Hellbenders in West Virginia……………………………………………………………...4
Study Objectives………………………………………………………………………….. 5
METHODS
Study Site Description……………………………………………………………………..5
Study Site Surveys…………………………………………………………………………7
Crayfish Luring Capture Technique……………………………………………………….8
Marking Technique………………………………………………………………………...9
RESULTS
Surveys and Search Effort…………………………………………………………………10
Morphometrics…………………………………………………………………………….10
1998-2009 Demographic Shift…………………………………………………………….11
Eleven-year Hellbender Growth………………………………………………………….. 11
Case Study of a Male Hellbender………………………………………………………….12
Crayfish Survey……………………………………………………………………………12
Evidence of Reproduction and Parental Care……………………………………………...13
Mudpuppies (Necturus maculosus)………………………………………………………..14
Wounds, Scars, Polydactylism and Mortality……………………………………………...14
Philopatry…………………………………………………………………………………..15
DISCUSSION
Methodology Comparison of West Fork Greenbrier Studies……………………………...16
Long-term Growth and Future Monitoring………………………………………………...17
Potential Impact of Surveys………………………………………………………………..20
Conclusions and Management Recommendations…………………………………………21
LITERATURE CITED…………………………………………………………………………22
APPENDIX………………………………………………………………………………………..25
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ACKNOWLEDGEMENTS
First and foremost, I must thank my mother Ann, whose is a bottomless source of strength and
inspiration in my life, and to whom I owe a debt which cannot be repaid. I am truly blessed to have her as
a mother and a best friend. Next, I thank my undergraduate advisors Drs. Mark and Alix Fink, Dr. Tom
Akre and Dr. David Buckalew at Longwood University for helping me to discover my passion for
ecology. Through their vast knowledge, and ultimately their friendship, rose a clarity of direction for my
academic path. I have a special thank you for my graduate advisor Dr. Thomas Pauley, who provided not
only valuable ecological insight, but invaluable life perspective when it was sorely needed. Along those
same lines, I am grateful for Dr. Jayme Waldron and her endless research knowledge and experience, as
well as helpful advice on some of life’s roadblocks.
At the risk of being unconventional, I am compelled to show gratitude to my research animal, the
Eastern Hellbender. From a very personal perspective, these beautiful creatures have really impacted my
life. Professionally, I had the opportunity to work with some fantastic people and organizations. I was
honored to spend four days with Matt Evans and several other people from the Smithsonian, George
Grall, a National Geographic photographer, and John Seyjagat, a curator for the National Aquarium in
Baltimore, Maryland. I appreciated their professional perspective on ecological research. I also was called
upon by the U.S. Forest Service to lead a two day survey of a Western Virginia tributary to verify reports
of possible hellbender sightings, and to educate several employees on effective hellbender surveying
techniques.
Thankfully, hellbenders are biologist magnets. With only a few exceptions, finding help for field
work was never an issue. When the rocks you need to lift to find hellbenders are often as large as a dinner
table, good help is not merely appreciated, it is essential. Personally, I owe many new friendships to
people wanting to see a live hellbender for the first time. I took great joy in showing others these
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fascinating amphibians, and in turn I met a lot of great people. Enough thanks cannot be expressed for
those who helped me out in the field. Many thanks to: Casey Bartkus, Casey Bradshaw, Jessica Curtis,
Matt Evans, John Feazell, David Fields, Mark Fink, Joe Freeman, George Grall, Kathy Grall, Jeff
Humphries, Aaron Gooley, Fred Huber, Scott Jones, Dawn Kirk, Joe McSherry, Kevin Messenger,
Rachel Mills, Katie Murphy, John Seyjagat, Nathan Shepard, Mike Sisson, James Stanton, Karen
Stevens, Steve Tanguay, Mark Tegges, and Kristen Trevey.
I have to give a special thanks to my “Ace in the hole” Joe Freeman. Almost without exception,
if I needed help, Joe drove several hours in from Maryland. Apart from spending six weekends out in the
field lifting huge rocks, becoming my most dependable help, and the best “one man campfire band in the
land,” Joe became a great personal friend. Also, I thank Dr. Mark Fink, for driving up from central
Virginia three weekends to help out in the field. A great mentor, friend, and champion rock-lifter, Mark is
owed many thanks.
Of course, I am exceedingly grateful to the ground work that Dr. Jeff Humphries laid in 19981999 that made this study possible. The hellbenders he tagged 11 years prior allowed me a unique
opportunity to gather some fantastic long-term growth and population data. A seasoned “benderer,” his
valuable inside knowledge on the study site and hellbender ecology has proved invaluable throughout all
aspects of my study. His many ideas and comments throughout the writing and review process have been
well appreciated. Once again, hellbenders have introduced me to a great biologist and a good friend.
Thanks to Joe Greathouse and The Good Zoo at Oglebay Park for possible research directions
early in my search for a hellbender thesis, and for loaning me survey equipment. A big thanks to Max
Nickerson, the man who literally co-wrote the book on hellbenders, for giving me confidence in the
research I was conducting. Also, I am grateful for him sharing his extensive experience on all aspects of
hellbender ecology, both past and present. An extra special thanks to Nancy Johnson and Johnson
Consulting Services for donating me two GPS units, a camera, and topographic software. Finally, I want
v
to thank my committee members Dr. Jeffrey May and Dr. Dan Evans for their helpful suggestions and
enduring my long-winded thesis defense. Partial funding for this study was provided by Marshall
University Graduate College. This project was completed under Marshall University Animal Use Protocol
Number 423. All animals I collected were done so under West Virginia Collecting Permit #2009-054.
vi
List of Figures
Figure 1. Location of study site along the West Fork of the Greenbrier River, Pocahontas County, West
Virginia.
Figure 2. Diagram of study reach.
Figure 3. Photo of diurnal rock-lifting survey technique.
Figure 4. Measuring apparatus and a recently captured hellbender.
Figure 5. Hellbender under a cover rock at night with only its head exposed.
Figure 6. Photo of marking technique.
Figure 7. Evidence of reproduction within study reach in 2009.
Figure 8. Fertilized hellbender egg.
Figure 9. Change in mass of the eleven 1998 recaptured hellbenders from the West Fork Greenbrier.
Figure 10. Smallest hellbender found during study.
Figure 11. 1998 West Fork of the Greenbrier hellbender population demographics.
Figure 12. 2009 West Fork of the Greenbrier hellbender population demographics.
Figure 13. Eleven-year growth curve for 1998 hellbenders recaptured in 2009 on the West Fork of the
Greenbrier.
Figure 14 . Photo of Mudpuppy (Necturus maculosus).
Figure 15. Photo of hellbender #0A0008347 missing feet on both his front left and rear left legs.
Figure 16. Photos of hellbender #008-866-349 in very poor condition.
Figure 17. Seasonal decline of body mass of male hellbender #0A00081134.
Figure 18. Swollen cloaca of male hellbender #0A00081134 captured on September 7th, 2009.
Figure 19. An example of polydactylism.
Figure 20. Photo of dead hellbender discovered September 5th, 2009 upstream from the study site.
Figure 21. Results of August 2009 crayfish survey.
Figure 22. The New River Crayfish, Cambarus (Hiaticambarus) chasmodactylus.
vii
List of Tables
Table 1. Eleven-year growth data of the eleven hellbenders recaptured in 2009.
Table 2. Discharge data for the West Fork of the Greenbrier in cubic feet per second.
viii
OVERVIEW OF FINDINGS
I processed thirty-eight hellbenders, encompassing 112 person-hours, on the West Fork of the
Greenbrier in Pocahontas County, West Virginia between April 25, 2009 and October 11, 2009. Eleven of
the original 29 hellbenders tagged within the study site in 1998 by Jeff Humphries were re-captured in the
2009 season. Table 1 is a list of all hellbenders captured, including their tag number, location, sex, total
length, snout-vent length, mass, body condition, reproductive condition, and visible injuries. I used both
diurnal rock- lifting and night surveys. Thirty of the hellbenders were captured within the original 1998
study stream reach, including all eleven 1998 recaptures. I found 19 “new” hellbenders within the site. Of
all hellbenders captured on the West Fork, 25 were male, 12 were female, and one was of undetermined
sex. The sex ratio was 2.1:1. Of these, 29 were captured once, 8 were captured twice, and one was
captured four times. Eight males and one female comprised the eleven re-capture events. I captured
twelve hellbenders (8 males, 4 females) during night surveys, and 26 (8 females, 16 male, and unknown
sex) during diurnal rock-lifting and snorkeling surveys. There was a marked size class shift in the 2009
population towards larger individuals compared to the 1998 population. Also, there was a dramatic shift
in sex ratio toward males in 2009, compared to a ratio of 1.06:1 eleven years prior. Of the 29 hellbenders
tagged within the West Fork site in 1998, 11 were recaptured in 2009. This is the first documentation of
long-term philopatry for Eastern Hellbenders. Eleven year mean growth of recaptured hellbenders is 3.43
cm (range 0.6cm - 4.5 cm, n=11). Contrary to the 1998 study, I found evidence of reproduction. I found
two nests sites, and an adult hellbender possibly guarding approximately 75 six-month old larvae. This
may be a rare example of extended parental care. Upon examining a loose egg near a nest rock, I noted
the embryo just beginning to cleave into four sections. Therefore, I am able to date with relative certainty
that the date of oviposition is September 3rd or Sept 4th. While I did notice several demographic shifts, I
did not document a decline. Also, the presence of 19 new hellbenders within the study site suggests
stability within the stream system. Overall, the West Fork of the Greenbrier likely represents a relatively
stable and viable population of hellbenders.
1
INTRODUCTION
Species Description
The Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) is a large, fully aquatic
salamander that prefers streams that are swift-flowing, highly oxygenated, and exhibit limited disturbance
(Green 1933; Bishop 1941; Nickerson and Mays 1973; Pfingsten and Downs 1989; Conant and
Collins1998). Habitat specialists, hellbenders need large, flat rocks for cover and nesting (Hillis and
Bellis, 1971; Nickerson and Mays, 1973; Nickerson et al., 2002; Humphries and Pauley, 2005).
The Eastern Hellbender ranges from southern New York to northern Georgia, west to Alabama,
and Mississippi, and a population in central Missouri (Nickerson and Mays, 1973; Petranka 1998). The
Ozark subspecies (Cryptobranchus alleganiensis bishopi) has populations in southern Missouri and
Northern Arkansas (Nickerson and Mays, 1973). The Ozark subspecies is characterized by smaller
spiracles, dorsal blotches instead of spots, increased mottling on the chin, a smooth pectoral lateral line
system, and a smaller overall body size (Grobman, 1943; Nickerson and Mays, 1973; Petranka, 1998).
One of North America’s largest salamanders, Eastern Hellbenders are characterized by a heavily
wrinkled, dorso-ventrally flattened body, keeled tail, and a large flat head (Green and Pauley, 1987).
Hellbenders average 50 cm in length, with a record length of 74 cm (Nickerson and Mays, 1973; Green
and Pauley, 1987; Petranka, 1998). While their coloration varies, hellbenders normally exhibit a dark,
spotted or blotched dorsum, and a plain, light venter. Utilizing cutaneous respiration, hellbenders have
loose, highly vascularized skin. Folds along the dorsal and ventral aspects of the body increase surface
area and allows for maximum gas exchange (Bishop, 1941). This method of respiration limits hellbenders
to cool, swiftly flowing streams where gas exchange is maximized (Ultsch and Duke, 1990).
Hellbenders exhibit slow growth, delayed maturity and low fecundity (Wheeler et al. 2003). This
life history strategy results in slow recovery from perturbations, leading to difficult and unique
2
conservation challenges (Congdon et al. 1993, 1994). Due to these specific adaptations and strict habitat
requirements, hellbenders are very sensitive to disturbance. Changes to stream systems, specifically
anthropomorphic alterations, often result in declines or extirpation of hellbenders. Several studies have
noted recent declines in hellbender populations across their range (Nickerson and Mays, 1973; Trauth et
al., 1992; Wheeler et al., 2003; Briggler et al., 2007; Foster et al., 2009). Trauth et al. (1992) noted a
decline from 370 hellbenders to 20 in the Spring River in Arkansas in only a 10 year span. Wheeler et al.
(2003) observed a 77% decline in both hellbender subspecies over a 22-year period in Missouri.
Declines
Hellbender declines can be attributed to several major causes. Perhaps the most significant factor
in these declines is habitat degradation (Nickerson and Mays, 1973; Williams et al., 1981; Trauth et al.,
1992; Nickerson et al. 2002; Wheeler et al., 2003; Humphries and Pauley, 2005). Logging, urban
development, and agricultural practices reduce canopy cover, and have the potential to increase water
temperatures. Such alterations decrease the amount of dissolved oxygen and can lower the respiratory
ability of hellbenders (Utlsch and Duke, 1990). Such practices also increase siltation, another major
potential cause of hellbender declines. Welsh and Ollivier (1998) suggest an increase in sedimentation
was a major cause of decline in the Pacific Giant Salamander (Dicamptodon tenebrosus). Interstitial
spaces of the stream substrate become filled with sediments and reduce macroinvertebrate prey, cover,
and habitat for larvae. While there is a paucity of information on larval hellbender habitat requirements,
sedimentation likely similarly affects hellbender larvae through alteration of this microhabitat and prey
availability (Nickerson et al., 2003). Dundee (1971) suggested that siltation, as well as general and
thermal pollution, was likely responsible for eliminating hellbenders from the Ohio River drainage.
Two other causes of hellbender decline for this region are acid mine drainage and impoundment
(Nickerson and Mays, 1973; Bury et al., 1980). Mine wastes cause anoxia and acidification to streams,
3
while impoundment and channelization alters the streams’ natural flow. Once swift, highly oxygenated
streams become slower and warmer, decreasing dissolved oxygen levels. Humphries (1999) suggests that
the lack of hellbenders in healthy streams today can possibly be explained by past acid mine drainage
issues that have since undergone remediation. Killing by fishermen who may wrongfully view
hellbenders as poisonous is also another potential source of decline (Nickerson and Mays, 1973).
No one cause is completely responsible for declines in hellbender populations. It is likely a
combination of factors, which will vary for different hellbender populations across their range.
Management and conservation decisions should be based on the specific stressors affecting a certain
population.
Hellbenders in West Virginia
Hellbenders historically are known from the Ohio River and were considered common in sections
near Ohio and West Virginia (Green, 1934). However, it is highly unlikely that hellbender populations
still exist in large rivers like the Ohio due to channelization, impoundment and siltation (Humphries,
1999). Eastern Hellbenders are considered endangered or a species of concern in most states where they
occur. In West Virginia, hellbenders are considered a species of concern (S2) by the West Virginia
Division of Natural Resources. The current major threats listed for hellbender populations in West
Virginia are habitat degradation, over-collection, and acid mine drainage. Over-collection, specifically in
West Virginia, may pose a significant threat to hellbenders. West Virginia provides no protection for the
hellbender, and general collection of all aquatic life requires only a Class B fishing license. As there is
currently a high demand for hellbenders in the pet, medicinal, and food trade in Asia, with some
salamanders selling for up to $3,500 per animal (Trauth et al., 1992; Briggler et al., 2007), over-collection
is likely a major cause of decline. However, to collect for scientific purposes a permit is required, yet
4
collection is unlimited for anyone with a West Virginia fishing license (Grandmaison et al., 2003). No
other state allows such unregulated collection practices.
Study Objectives
This study seeks to further our knowledge and understanding of the ecology of the Eastern
Hellbender in West Virginia. Specifically, it is my goal to document current demographic and population
status and trends of a hellbender population on the West Fork of the Greenbrier, Pocahontas County, West
Virginia. Historical data for this population was provided by Jeff Humphries in his 1998-1999 Marshall
University masters degree thesis research. I compared data I collected in 2009 to data collected in 1998.
Specifically, I am interested in long-term (eleven-year) hellbender growth, philopatry, population
dynamics, reproduction, and overall ecological trends. It is also my goal to lay further groundwork for
future studies and add to our overall knowledge of this fascinating and unique salamander species.
METHODS
Study Site Description
This study took place on the West Fork of the Greenbrier River, 1.7 miles north of Durbin, in
northern Pocahontas County, West Virginia (Fig.1). The Greenbrier River is a tributary of the New River,
which is in the Mississippi River drainage. The West Fork begins on the eastern slopes of Shaver’s
Mountain, flows southwest, and forms a watershed inside the Monongahela National Forest. The
Monongahela National Forest provides protection from development for this section of stream and its
headwaters. The West Fork watershed exhibits limited disturbance, mainly in the form of horse trails,
campsites and recreational fishing. It should be noted that just upstream of the study area is a popular
fishing hole that is frequented regularly by trout fishermen.
5
The immediate surrounding watershed and riparian zone is characterized by a steep slope with a
densely vegetated mixture of hemlock, rhododendron, and northern hardwood species on the south side of
the site. The north side of the site is characterized by a narrow floodplain, sparsely vegetated by
rhododendron, various shrubs and a few large hardwoods. Also on the north side of the study site is a
forest service road that doubles as a horse and hiking trail. Non-forest service authorized vehicles are not
permitted on this road and vehicular travel is therefore limited.
The stream, which encompasses the study site, is characterized by shale or limestone bedrock,
which underlies the entire stream. The stream substrate is comprised mainly of gravel and cobble, with
sections of sand and silt in the slower sections. Throughout the stream are many large, flat rocks, varying
in dimension from the size of a car tire to the size of a large dining room table. Normally consisting of
limestone or igneous rock, it is these rocks that provide shelter and habitat for hellbenders. However,
other aquatic organisms, including crayfishes, mudpuppies (Necturus maculosus) and various stream
fishes can also be found under these large rocks. Hydrodynamically, the stream consists of a series of fast
flowing rapids, fast flowing runs, and a few deep pools. During normal flow, the majority of the stream is
less than 80 cm deep. The deepest pools are generally less than 2.5 m deep.
My study site encompassed Jeff Humphries’s 1998 site, which was a stream section 216 meters
long and approximately 20 meters wide. However, I extended the site both upstream and downstream
approximately 50 meters to increase the likelihood of capturing 1998 tagged hellbenders. Three relatively
deep, slower flow runs and two areas of higher flowing rapids characterized the original 1998 site.
Flooding and increased flow occurred during and after major precipitation events, and the stream was
flooded and inaccessible almost the entire month of May. Stream temperature ranged from 3°C in winter
to 24°C in August; however the stream normally remained below 21°C most of the summer. It should be
noted, that anecdotally the stream appeared to have more silt to Jeff Humphries on the several occasions
he aided in field work in 2009 compared to 1998. Mean stream discharge for 2009 varied from a high of
487.1 cfs (cubic feet per second) in May 2009 to a low of 28.9 cfs in September 2009 (Table 2).
6
Humphries used a 9m x 9m (3 quadrants wide by 24 quadrants long) grid system to map locations
of hellbenders. I re-established this grid system lengthwise for the 2009 season using reflective flagging
tape along the shoreline every ten meters. Flags were numbered from 0 to 11, with .5 increments
representing 10 meters. The top (upstream) of the study site started with flag 0 and flag numbers
increased and stopped at 11 at the bottom of the study site (Fig.2). This allowed me to precisely document
the locations of 1998 hellbender recaptures for later comparison with their original capture locations
eleven years prior.
Study Site Surveys
I implemented both nocturnal and diurnal surveys on my study site; however the majority of time
and effort was focused on daytime searches. Daytime searches typically started from 10:00 -11:00 AM
until 4:00 -6:00 PM, or until searchers were either extremely cold and/or exhausted. A minimum of two
people were required for effective daytime surveys. I was in the stream with a mask and snorkel looking
under large rocks while the other searcher/searchers slowly lifted the rock (Fig. 3). Almost without
exception the use of a log peavey was required to aid in lifting the large and heavy rocks. If a hellbender
was under a rock, I captured it by hand and quickly transferred it into a mesh bag. I then took the animal
to shore and collected the following data: date and time of capture, exact global positioning satellite
(GPS) position within the grid, the presence of a previously implanted Passive Integrated Transponder
(P.I.T.) tag, sex, total length, snout-vent length, mass, injuries/scars, and in males the degree of swelling
of the cloaca (not swollen, slightly swollen, swollen, very swollen). Various other descriptive data was
noted if apparent, i.e. the presence of milt, presence of eggs, general overall health. I measured total
length and snout-vent length with a 10 cm diameter PVC pipe cut in half with measuring tape glued
inside (Fig. 4). This aided in keeping the hellbender straight during measurement. I used a 300g, 600g or
1000g Pesola scale attached to a heavy-duty plastic bag (tared) to measure mass to the nearest gram. If the
7
hellbender was a new capture, I injected it with a P.I.T. tag. I also took DNA samples for use in a Purdue
University genetic study by cutting a small section of skin from the top of the tail. The sample was then
placed in a vial with 70% alcohol, and date, sex, and location were noted. Once I recorded all data, I
promptly returned the hellbender to the site of capture. Great care was taken to return the rock to its
original position and orientation, and I released the hellbender directly beside the entrance to underneath
the rock. It often took two to three days to exhaustively search the study site with this diurnal survey
method.
I also conducted nocturnal visual surveys for active hellbenders. Typically, I began searching for
hellbenders just after dark, with up to as many as five people searching. Starting downstream of the site, I
would work upstream using headlamps and flashlights to search the bottom for active hellbenders. Once a
hellbender was found, all searching halted and I recorded the aforementioned data. I then released the
hellbender at the original site of capture and then would resume the search. We continued searching until
we had completely explored the whole study site. A typical survey lasted 45 minutes to 2.5 hours,
depending on the number of hellbenders captured and people surveying. It should be noted that this
method is often difficult to feasibly and reliably implement during above normal stream flow. I often was
able to effectively survey the study site during the day, however, at night the higher flow made it
impossible to clearly see the stream bottom. I was often only able to search certain areas of the site during
anything other than optimal conditions.
Crayfish Luring Capture Technique
During night surveys, I would often see a hellbender with its head just barely sticking out from
underneath an extremely large rock (Fig. 5). This rock was too massive to lift in a daytime survey, and
this hellbender never seemed to be active and leave this rock at night. On two separate occasions I was
able to lure this hellbender out using a crushed crayfish placed approximately 10-20 cm outside of the
8
entrance to the rock. I then waited for 10 to 15 minutes for this hellbender to slowly leave the rock
enough to effectively grab and capture by hand. After discovering the success of this technique, I used it
on other occasions to lure out hellbenders from underneath cover rocks at night. Surprisingly, direct and
extended exposure to search lights did not seem to deter the hellbenders from venturing out to eat the
crayfish. Also interesting to note, I was only able to perform this technique a maximum of two times for
the same hellbender in a single season. After one to two captures using this method, the hellbender would
retreat under the rock if searchers came within approximately a meter of its rock. This retreat behavior
was still present up to two months from last capture using the crayfish luring method. This may suggest
some form of learned behavior and an ability to remember negative stimuli for at least a period of 3 to 4
months. While this technique was not necessarily part of the sampling protocol, it was an effective
capture technique in certain cases.
Marking Technique
After a hellbender’s initial capture, I tagged each hellbender with a P.I.T. tag. All tags were 12
mm, 125 kHz Biomark TX1411SSL. Each tag was sterilized in 100% rubbing alcohol prior to being
implanted, and I injected the tag into the fatty dorsal region of the base of the tail (Fig. 6). I then recorded
the tag number with a HomeAgain brand microchip reader and returned the hellbender to its original site
of capture. If the hellbender was captured under a rock, an effort was made to return it to that specific
rock. The processing time took approximately 10 to 15 minutes per new hellbender. If I recaptured a
tagged hellbender, I simply scanned the tag with the reader and collected the same measurements.
Wounds from the injection of P.I.T. tags were minimal and healed with no sign of complications. There
was no evidence that any tags shifted or were expelled, and this method of tagging appeared to have little
to no adverse effects on the animal. P.I.T. tags from hellbenders tagged in 1998 also showed no sign of
shifting.
9
RESULTS
Surveys and Search Effort
Twenty-eight survey events (19 diurnal, 9 nocturnal) and 112 adjusted person hours resulted in
the capture of 38 hellbenders on the West Fork of the Greenbrier from April 24th to October 10, 2009. I
captured twelve hellbenders (8 males, 4 females) during nocturnal surveys, and 26 (8 females, 17 males,
and unknown sex) during diurnal rock-lifting and snorkeling surveys. Person hours were adjusted during
diurnal surveys to include only those actively searching. This was normally the equivalent of two people,
one person to lift the rock, and one to snorkel underneath. Even if there were more than two people,
others were not actively searching and were considered observers. I quantified survey efforts this way in
order to avoid biased search effort data. Often times I would have up to seven people in the stream,
however, only one rock was lifted at a time. Actual person hours were 186 for the 2009 season. Surveys
ranged in their effectiveness for finding hellbenders, ranging from zero hellbenders per hour to 1.25
hellbenders per hour.
Morphometrics
I captured and measured 38 hellbenders in 2009. Mean total length was 45.86 cm. Mean total
length for males was 43.70 cm and ranged from 36 cm to 49 cm. Mean total length for females was 49.67
cm and ranged from 43 cm to 57 cm. I found a hellbender of unknown sex that was 23 cm in total length
and was the smallest hellbender captured during my study (Fig 10).
Mean mass of all hellbenders was 537.5 grams, ranging from 79.0 g to >1000 g. (One very large
female was over 1000 g, and I did not have a >1000 g scale at the time.) It should be noted that the spring
10
did go past the 1000 g mark, but did not bottom out the scale. Therefore it is likely that an approximation
of 1000 g for this animal will not adversely affect the data. Mean mass for males was 504.45 and ranged
from 260 g to 720 g. Mean mass for females was 697.31 and ranged from 420 g to 1020 g.
1998-2009 Demographic Shift
I found a shift in size classes of hellbenders in the 2009 study towards larger salamanders (Fig.
12). However, I did find 1st year gilled larvae in this study. This represents the smallest size class (4-6 cm
total length), but they were not included as I could not capture them without jeopardizing them to
potential predators and general undue stress. Therefore I did not include them in my size class comparison
figure. I found one individual that was 23 cm in total length; however, sex could not be confidently
determined and was not used in analysis.
I found a notable sex shift toward male hellbenders in the 2009 study. In 1998, Jeff Humphries
captured 19 males, 18 females, and 4 of unknown sex (Fig. 11). The sex ratio for hellbenders in the study
stream was 1.06:1. In 2009, I captured 25 were male, 12 were female, and one was of undetermined sex
(Fig. 12). The sex ratio was 2.1:1.
Eleven-Year Hellbender Growth
I found 11 hellbenders ( 8 males and 3 females) that had been previously tagged in 1998 within
the study site (Table 1). Mean growth over 11 years was 3.38 cm, with growth ranging from 0.6 cm to 5.2
cm (Fig. 13). All recaptured 1998 hellbenders were over 40 cm in total length in 2009. Average annual
growth would therefore be estimated at 0.31 cm. Mean gain in mass was 103.4 g, with a range of -225 g
to 210 g (Fig. 9). One particular salamander, (P.I.T. # 008-866-349), lost 225 g in mass, and was in very
poor condition when captured (Fig. 16).
11
Case Study of a Male Hellbender
I captured a male hellbender (#0A00081134) four times during the course of my study. He was
first captured May 24, and was recaptured July 7th, August 10th, and September 7th of 2009. This was the
only hellbender recaptured more than once, and is the only hellbender that I could follow and examine
throughout the 2009 season. As the season progressed this hellbender showed a trend toward losing
weight as mating season approached (Fig. 17). Also, I was able to note the occurrence and healing of
wounds over time. On his initial capture, this hellbender showed no significant wounds or scarring.
However, on the next capture in July, he exhibited fresh bite scars on his head, and three cuts below his
right eye. I captured him again in August and he had a fresh scar behind his left front leg, and scarring by
his right eye. The bite scar on his head was barely visible. On the final recapture in early September, he
showed no signs of scarring. His cloaca was extremely swollen and he was milting upon being handled
(Fig. 18). It is clear that while he showed a 15% percent drop in mass (620g to 525g) throughout the
season, it did not seem to affect his ability to reproduce. The stresses of preparing for breeding season are
likely the cause of this hellbenders change in body mass. This is likely not uncommon for male
hellbenders approaching breeding season.
Crayfish Survey
I conducted a crayfish survey on August 14th to help determine the abundance of crayfish, the
staple food source of hellbenders, within the study site. I documented the presence/absence of crayfish
under 100 rocks greater than 30 cm wide chosen at random (Fig. 21). I also noted the presence of fishes
under rocks. Rocks with hellbenders underneath were not counted in the survey. The vast majority of
crayfish encountered in the West Fork were the New River Crayfish, Cambarus (Hiaticambarus)
chasmodactylus (Fig. 22).
12
Evidence of Reproduction and Parental Care
In contrast to the 1998 study, I documented evidence of reproduction both in and out of the study
site. On May 24, approximately 50 to 75 larval hellbenders were found under a large rock along with a
large adult hellbender in the downstream section of the study site (Fig.7). The larvae were all
approximately 4 to 6 centimeters in total length. The sex of the adult hellbender was not determined
because it evaded capture. It is presumed that it was a male guarding fall 2008 hatchlings (J. Humphries,
personal communication). This is potentially a rare example of extended parental care of larvae by
hellbenders. I also found a larval hellbender near a large rock that had just been lifted. I did not attempt to
capture it for fear of injury. However, I was able to view it long enough to confirm its identity as a first
year larval hellbender. It also was approximately 4 to 6 centimeters in total length and was found at a
depth of 0.5 meters. It is not clear if this particular larva was initially under the rock or in the interstitial
spaces of the gravel and cobble that surrounded the large rock.
I also documented two separate nesting sites, one within the original study site, and one several
100 meters upstream of the study site. The first nest site was found on September 5th at the upstream end
of the site (Flag 1), and was discovered by the presence of a few loose eggs protruding from the side of
the rock (Fig.7). This was fortunate as I was able to identify a nest rock without lifting it and potentially
compromising the nest site. This also allowed me the unique opportunity to examine a loose and
unguarded egg. The egg had just very recently been fertilized as the embryo had just started to cleave into
4 sections (Fig. 8). This leads me to approximate the date of oviposition between September 3rd and
September 4th. Another nest site was discovered several 100 meters upstream of the study site on
September 6th. A male (#985120030063764) was guarding approximately 200-300 eggs beneath a large
rock.
13
Mudpuppies (Necturus maculosus)
Throughout the course of my study, I found 3 mudpuppies. All sightings occurred in mid-August
between the 11th and 15th. All were found underneath large rocks that would also be suitable hellbender
habitat. The largest one was 9.2 cm TL (Fig. 14).
Wounds, Scars, Polydactylism and Mortality
Just over half (20) of the hellbenders captured exhibited wounds or scars. Injuries included
missing limbs (stubs), missing toes, bite wounds and scarring from bite wounds, eye injuries, a broken
shoulder, notches in tail, and open gashes. One male was missing his front left foot, rear left foot, and two
toes on his rear right foot (Fig. 15). I recaptured this individual once, and both times he appeared to be in
good general health. The most common injuries or past injuries were bite marks and scars to the head,
with 11 hellbenders exhibiting evidence of being bitten in the head by another hellbender. Another
hellbender had a broken left shoulder and a large gash under his front left leg (Fig. 16). This hellbender
was a recapture from 1998 and had lost over 35% of his body mass (-215 g). There did not appear to be a
correlation with sex to this type of injury as 3 females had bite scars on their heads. These findings were
consistent with findings made by Jeff Humphries in 1998, as 49% of captured hellbenders had either
missing limbs or toes, and 29% had major wounds or scars from major wounds present (Humphries,
1999).
I also found polydactylism present in my study. One female hellbender had nine toes on her rear
right foot (Fig. 19). This has been seen in North Carolina hellbender populations and is most likely a
complication of limb regeneration (Jeff Humphries, personal communication).
I documented a case of hellbender mortality. On September 5th, 2009 I found a dead male
hellbender (42.5 cm total length, 32 cm snout/vent length) upstream from the study site. This male had a
14
swollen cloaca, and was assumed to be in decent reproductive status. I found him partially protruding
from under the upstream end of a large rock, and he was partially disemboweled and just starting to
decompose (Fig. 20). It appeared that his stomach had been cut with a knife, and there was no evidence
that anything had fed on his remains. While his cause of death cannot be known for certain, it is likely he
was killed by a fisherman.
Philopatry
I documented site fidelity among hellbenders in my study. Over a third (11 of 29) of the
hellbenders tagged within the study site in 1998 were still found within the site 11 years later. One
hellbender, a large female, was found within a meter of the same rock where she was found in 1998
(Humphries, personal communication).
DISCUSSION
Several studies have noted the decline of hellbender populations in recent years (Wheeler et al.,
2003; Briggler et al., 2007; Foster et al., 2009). Anecdotal accounts of historical records and abundance
compared with recent data have indicated a strong decline and loss of several historical populations of
hellbenders across their range. In this study, I sought to find out if the hellbender population of the West
Fork of the Greenbrier was declining.
In my study, demographic data from 1998 were compared to data collected in 2009 to document
any demographic changes within the hellbender population in the West Fork of the Greenbrier. I found a
dramatic shift in sex ratio, with males dominating the population more than two to one (Fig.12). A 2009
New York study also documented a shift toward males in several populations (Foster et al., 2009). In that
15
study, demographic data from the 1980’s was compared to 2004 and 2005 data. They noted an overall sex
shift from 0.8:1 historic sex ratio to a 1.8:1 ratio. Female hellbenders declined in all of their study sites.
This shift towards a male dominated population was also coupled with a general decline in hellbender
abundance (Foster et al., 2009). A recent Pennsylvania study also found a hellbender population with a
2:1 sex ratio (Llewellyn and Petokas, unpublished data).
Methodology Comparison of West Fork Greenbrier Studies
I employed diurnal rock-lifting surveys for the majority of sampling in my study. This is in
contrast to the Humphries 1998 study where night surveys comprised the majority of sampling. I
encountered several problems during night searches. Unless weather and stream conditions were optimal,
limited visibility affected my ability to effectively search the entire study site. For almost half of my field
season, the stream level was too high and the flow too fast to allow me sufficient visibility to search
effectively. Many nights I was only able to search the very shallow sections of the stream. Also, if it had
recently rained, the stream would rise quickly and hinder visibility. In addition, night surveys are biased
and target only active hellbenders. Smaller size classes are likely either not as active at night, and/or are
more difficult to see on the stream bottom (Personal observation). The increased use of nocturnal surveys
in 1998 likely limited the detection of smaller size classes of hellbenders (Humphries and Pauley, 2005).
This also likely limited the detection of nests and gilled larvae.
Diurnal rock-lifting was the most efficient and successful method in a recent study comparing
three hellbender capture methods (Foster et al., 2008). While this study did not test nocturnal visual
searches, it was clear that rock-lifting was the best method. This technique coupled with snorkeling is the
method thought to produce multiple age groups of non-gilled and adult hellbenders, and all sizes of gilled
larvae within short sampling periods (Nickerson and Krysko, 2003). However, during breeding season,
this method may disrupt nest sites and disturb or kill eggs and larvae (Williams et al. 1983). I was aware
16
of this drawback, and during the breeding season where eggs were being deposited and guarded, I
modified my technique slightly. Beginning late August, I would have the rock-lifter very slowly lift a
potential nest rock to approximately 10 centimeters off the stream bottom. I then implemented the use of a
waterproof flashlight to peer underneath rocks after the silt had settled. I feel this slight modification
limited the disturbance to a potential nest sight by not completely uncovering and disrupting a nest
(Personal observation). Twice during my study, I located nest sites. Upon discovery, I would estimate the
number of eggs, and slowly return the rock back to its original position. On one occasion I was able to
easily grab the guarding male, collected data, and returned him to his nest.
Long-term growth and Future Monitoring
Hellbenders are long-lived salamanders, living up to 55 years in captivity (Nigrelli, 1954). They
are also one of the largest salamanders in the world, reaching lengths of up to 74 cm (Bishop, 1941;
Nickerson and Mays, 1973). Displaying indeterminate growth, hellbenders grow their entire lives.
However, very little is known about their longevity under “non-captive conditions” (Nickerson and Mays,
1973). A length-age relationship was derived from Ozark hellbenders, Cryptobranchus alleganiensis
bishopi, in the North Fork of the White River, Missouri (Peterson et al., 1983). Age estimates are
possible for hellbenders up to around 40 cm using the following equation:
Age (months) = (1/-0.0127)ln(5.2193 + (-0.0127)TL(mm)) + 120 (Peterson et al., 1983)
This estimate, however, is based upon the Ozark subspecies, which generally is slightly smaller on
average than the Eastern subspecies (Nickerson and Mays, 1973). This would likely skew estimates for
the Eastern Hellbenders found in this study. A later review of two studies (Taber et al., 1975; Peterson et
al., 1983) found that Eastern Hellbenders growth is greater and more variable than the Ozark subspecies
(Peterson et al., 1985). Long-term growth data of large salamanders is severely lacking. Age estimates of
hellbenders >43 cm is difficult due to the variation of individual growth, and the decreasing growth in
17
these larger size classes (Westrheim and Ricker, 1978). Therefore, growth of large classes of salamanders
is largely unknown. This raises several study questions. How fast do hellbenders on the West Fork of the
Greenbrier grow? Do salamanders vary in growth rates among individuals in a population? Is this Eastern
West Virginia population representative of other hellbender populations?
Of the 29 hellbenders tagged within the site in 1998, I found 11 in 2009. All were greater than 40
cm. Mean 11-year growth for all 11 1998 hellbenders was 3.66 cm. Growth rates varied among
individuals, with one hellbender growing only 0.6 cm, and another 5.2 cm (Table 1). Four individuals
were very similar in size in 1998 (40, 40.5, 40.5, 40.8 cm). However, growth was 3.2, 4, 5, and 1.7 cm,
respectively. The two largest salamanders (55 and 56 cm, both female) also showed great variation in
growth. The 55 cm hellbender measured in my study grew 4 cm in 11 years, while the 56 cm animal grew
only 0.6 cm. The 55 cm hellbender grew 6.6 times more than her counterpart. Also, it should be noted that
0.6 cm is small, and could easily be within the margin of error during the measuring process. Effectively
it is possible, though not likely, that this female did not grow at all.
In order to determine if food availability may be a factor, I conducted a crayfish survey. Crayfish
make up a vast majority of the hellbender’s diet and were found to make up approximately 87.5% of
stomach content in 40 Ozark hellbenders (Nickerson and Selby, 1969 unpublished data). Another study
found crayfish to be present in 81% of the stomachs of 108 hellbenders (Peterson et al., 1989). As
hellbenders were found to be the primary predator of crayfish in streams they occupy (Dierenfeld et al.,
2009), crayfish density data is an important aspect of hellbender ecology. Crayfish populations are
considered low if 0-30% of rocks revealed crayfish, moderate if 31-60% revealed crayfish, and high if ≥
60% of rocks revealed crayfish (Nickerson et al., 2003). I found crayfish were in moderate abundance at
my site, with 43 percent of the rocks sampled having at least 1crayfish underneath. The very large
Cambarus (Hiaticambarus) chasmodactylus was the crayfish species I most often encountered in the
West Fork of the Greenbrier. There was a moderate abundance of crayfish throughout the study period,
and I doubt prey availability is a problem for hellbenders at my study site.
18
Even if I take the greatest amount of growth documented in 11 years, 5.2 cm, and liberally
estimate annual growth, it still is only 0.47 cm a year. This is a very slow growth rate for a salamander
that can reach lengths in excess of 70 cm. Current published estimates of age for non-captive hellbenders
are approximately 30 years (Taber et al., 1975; Petranka 1998). However, based on findings in this study,
I believe many salamanders I found to be over 50 years in age.
Throughout my study, 12 hellbenders were able to evade capture. It is certainly possible, and
probably likely, that some of those were hellbenders tagged in 1998. My work laid the foundation for
future demographic studies on this stream by tagging 27 “new” hellbenders. Philopatry, reproduction, and
movement can also be examined and compared to data from this study in the future. Several questions
require future investigation, including but not limited to: Is the sex ratio shift towards males cyclical, or
does it represent a long-term trend for the population? Based on reproduction findings, is there sufficient
juvenile recruitment in this stream? Is this adult dominated population representative, or are juveniles not
detected? Is this population truly stable, and if so, will this population continue to remain stable?
The sex ratio shift I noted remains enigmatic. One hypothesis, which remains untested, is the
potential of an unknown pollutant which may have a masculinizing effect on hellbenders in the stream
(M. Nickerson, personal communication). I believe that this is unlikely, as the study stream is within the
Monongahela National Forest has limited disturbance from pollutants. It is likely that this shift in sex
ratio is an accurate representation of the demographic composition in this stream as the survey method I
employed is the most comprehensive of all hellbender surveying methods (Nickerson and Krysko, 2003;
Foster et al., 2008).
Perhaps the most likely explanation for the sex ratio shift I found is the result of female
emigration and movement. A recent West Virginia study found that female hellbenders moved more
frequently, and moved greater distances than males (Greathouse, 2006). This increased female movement
may explain my low number of female recaptures from 1998. Female hellbenders tagged in 1998 may
19
simply have moved out of the site. This however does not explain the overall sex ratio (both “new” and
1998 hellbenders) I documented in my study. Future studies could help determine if this is a true longterm trend for this population.
Potential Impact of Surveys
As the survey progressed, I noticed that it became increasingly more difficult to find
hellbenders within the study site. I also noticed that many of the rocks that previously sheltered
hellbenders often no longer were used by hellbenders. On many occasions, several of the rocks that
produced hellbenders were now being used by rock bass and other fish. I took great efforts to return the
rock to as close to its original positioning as physically possible, but often that was very difficult as many
of these rocks were sealed by sediment. Also, upon lifting large shelter rocks, several smaller rocks would
shift and trying to recreate the exact original position and orientation of that rock was impossible. The
disturbance of this “seal” likely creates a subpar micro-habitat for use as a hellbender shelter rock. The
amount of time until that rock becomes suitable for shelter again warrants future investigation. The 1998
study primarily implemented nocturnal surveys and likely had less of an impact on hellbender habitat. I
focused more on diurnal surveys and lifted more rocks than the previous study. The lower impact of the
1998 study likely did not displace many hellbenders from the study site, thus allowing for them to be
found 11 years later. The potential return of a particular hellbender to a particular rock after disturbance
could also be a future study question. When biologists speculate about the potential causes of decline in
hellbender populations, particularly ones that have been actively surveyed for several decades, we must
not under-estimate the impacts of scientific surveys.
20
Conclusions and Management Recommendations
Overall, I did not document a decline in abundance in this population of hellbenders on the West
Fork of the Greenbrier. Furthermore, I documented two nest sites, evidence of potential extended parental
care, and gilled larvae. Also, 19 new hellbenders were found in the study site. These findings strongly
suggest that hellbender populations on the West Fork of the Greenbrier are currently viable and relatively
stable. While the evidence of reproduction I observed is in contrast to the previous study 11 years prior, it
is likely due to a difference in search methods. I believe that this stream could potentially serve as a
reference stream, and may represent a system in which hellbender populations can remain stable under
continued protection and monitoring. This is not to say that this stream is pristine and represents historical
conditions. The West Fork of the Greenbrier likely represents some of the best hellbender habitat in West
Virginia and should be managed and monitored to ensure hellbender populations remain stable.
Sedimentation from an adjacent forest service road, incidental killing by fisherman, and collection are still
likely causes of potential future decline for hellbenders in the West Fork of the Greenbrier if not
regulated.
21
LITERATURE CITED
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Briggler, J., J. Utrup, C. Davidson, J. Humphries, J. Groves, T. Johnson, J. Ettling, M. Wanner, K.
Traylor-Holzer, D. Reed, V. Lindgren, and O. Byers (Eds.) 2007. Hellbender Population and
Habitat Viability Assessment: Final Report.
Bury, R.B., C.K. Dodd, Jr., and G.M. Fellers. 1980. Conservation of the Amphibia of the United States: a
review. Resource Publication 134, U.S. Fish and Wildlife Service, Washington, D.C.,34p.
Conant, R.A. and J.T. Collins. 1998. A field guide to reptiles and amphibians of eastern and central North
America, Third edition.
Congdon, J.D., A.E. Dunham, and R.C. Van Loben Sels. 1993. Delayed sexual maturity and
demographics of Blanding’s Turtles (Emydoidea blandingii): implications for conservation and
management of long-lived organisms. Conservation Biology 7:826-833.
Congdon, J.D., A.E. Dunham, and R.C. Van Loben Sels. 1994. Demographics of Common Snapping
Turtles (Chelydra serpentina): Implications for conservation and management of long-lived
organisms. American Zoologist 34:397-408.
Dierenfeld, E., McGraw, J., Fritsche, K., Briggler, J., and J. Ettling. 2009. Nutrient composition of
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Dundee, H. A. 1971. Cryptobranchus and Cryptobranchus alleganiensis. Catalogue of American
Amphibians and Reptiles. SSAR 101.1-101.4.
Foster, R.L., A.M. McMillan, A.R. Breisch and K.J. Roblee. 2008. Analysis and comparison of three
capture methods for the Easter Hellbender (Cryptobranchus alleganiensis alleganiensis).
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Foster, R.L., A.M. McMillan, and K.J. Roblee. 2009. Population status of hellbender salamanders
(Cryptobranchus alleganiensis) in the Allegheny River drainage of New York State.
Grandmaison, D., Mayasich, J., and C. Phillips. 2003. Eastern hellbender status assessment report.
Natural Resources Research Institute. Duluth, MN.
Greathouse, J. 2006. Monitoring of the Eastern hellbender, Cryptobranchus alleganiensis alleganiensis,
in five Ohio River tributary streams in the Northern Panhandle of West Virginia. (Technical
report submitted to West Virginia Division of Wildlife). 93 pp.
Green, N.B. 1934. Cryptobranchus alleganiensis in West Virginia. Proc. W.Va. Academy of Science
7:28-30.
22
Green, N.B. and T. K. Pauley. 1987. Amphibians and Reptiles in West Virginia. University of Pittsburgh
Press. Pittsburgh, PA.
Grobman A.B. 1943. Notes on salamanders with the description of a new species of Cryptobranchus.
Occasional Papers of the Museum of Zoology 470:1-13.
Hillis, R.E. and E.D. Bellis. 1971. Some aspects of the ecology of the hellbender Cryptobranchus
alleganiensis alleganiensis, in a Pennsylvania stream. Journal of Herpetology 5:121-126.
Humphries, W.J. 1999. Ecology and population demography of the hellbender, Cryptobranchus
alleganiensis, in West Virginia. M.S. Thesis, Marshall University, Huntington, WV.
Humphries, W. J. and T. K. Pauley. 2005. Life history of the Hellbender,
Cryptobranchus alleganiensis, in a West Virginia stream. American Midland Naturalist 154:135-142.
Nickerson, M.A., K.L. Krysko, and R.D. Owen. 2002. Ecological status of the hellbender
(Cryptobranchus alleganiensis) and the mudpuppy (Necturus maculosus) salamanders in the
Great Smoky Mountains National Park. Journal of North Carolina Academy of Science 118:2734.
Nickerson, M. A. and K. L. Krysko. 2003. Surveying for hellbender salamanders,
Cryptobranchus alleganiensis (Daudin): A review and critique. Applied Herpetology 1:37-44.
Nickerson, M. A. and C. E. Mays. 1973. The Hellbenders: North American “giant salamanders”.
Milwaukee Public Museum. Milwaukee, WI.
Nickerson, M.A. and M. Selby. 1969. Unpublished data. Taken from Nickerson, M. A. and C. E. Mays.
1973. The Hellbenders: North American “giant salamanders”. Milwaukee Public Museum.
Milwaukee, WI.
Nigrelli, R. 1954. Some longevity records of vertebrates. Transactions of the New York Academy of
Sciences. 1954(16):296-299.
Peterson, C. L., R. F. Wilkinson Jr., M. S. Topping, and D. E. Metter. 1983. Age and growth of the Ozark
Hellbender (Cryptobranchus alleganiensis bishopi). Copeia 1983(1):225-231.
Peterson, C. L., Topping, M. S.,Wilkinson, R. F., Taber, C. A. 1985. Examination of long term growth of
Cryptobranchus alleganiensis predicted by linear regression models. Copeia 1985(2): 492-496.
Peterson, C. L., Topping, M. S.,Wilkinson. 1989. Seasonal food habits of Cryptobranchus alleganiensis
(Caudata: Cryptobranchidae). The Southwestern Naturalist 34(3):348-441.
Petranka, J. W. 1998. Salamanders of the United States and Canada. Smithsonian Institution Press,
Washington,DC.
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Vol. 7 No. 2.
23
Taber, C. A., R. F. Wilkinson Jr., and M.S. Topping. 1975. Age and Growth of Hellbenders in the
Niangua River, Missouri. Copeia 1975(4):633-639.
Trauth, S.E., J.D. Wilhide and P. Daniel. 1992. Status of the Ozark hellbender, Cryptobranchus bishopi
(Urodela: Cryptobranchidae), in the Spring River, Fulton County, Arkansas. Proceedings of the
Arkansas Academy of Science 46:83-86.
Ultsch, G.R. and J.T. Duke. 1990. Gas exchange and habitat selection in the aquatic salamanders
Necturus maculosus and Cryptobranchus alleganiensis. Oecologia 83(2):250-258.
Welsh, H.H. and L.M. Ollivier. 1998. Stream amphibians as indicators of ecosystem stress: a case study
from Califorinia’s redwoods. Ecological Applications 8: 1118-1132.
Westrheim, S.J. and W.E. Ricker. 1978. Bias in using an age−length key to estimate age-frequency
distributions. Journal of the Fisheries Research Board of Canada 35:184-189.
Wheeler, B. A., E. A. Prosen, A. Mathis, and R. F. Wilkinson. 2003. Population
declines of a long-lived salamander: A 20 + - year study of hellbenders, Cryptobranchus alleganiensis.
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24
APPENDIX
Mass (g)
P.I.T. tag #
Sex
TL 1998
TL 2009 Growth(cm)
1998 Mass (g) 2009 Δ Mass (g)
006-798-526
M
38.3
42.5
4.20
330
401
71
0A00085974
M
39
43.5
4.50
335
545
210
0A00085612
M
40
43.25
3.25
280
425
145
0A00054800
M
40.5
44.5
4.00
500
465
-35
0A00081134
M
40.5
45.5
5.00
350
564
214
0A00083847
M
40.8
42.5
1.70
381
541
160
0A00083243
M
42.8
46.5
3.70
430
630
200
008-127-071
F
45.3
50.5
5.20
405
615
210
008-866-349
M
47.5
48.5
1.00
640
415
-225
007-829-630
F
51
55
4.00
655
760
105
0A00083714
F
55.4
56
0.60
893
975
82
Table 1. Eleven-year growth data of the 11 1998 hellbenders recaptured in 2009. Mean growth (total
length) over 11 years was 3.38 cm, with growth ranging from 0.6 cm to 5.2 cm. Average gain in
mass was 103.4 g, with a range of -225 g to 210 g.
25
00060, Discharge, cubic feet per second,
Monthly mean in cfs (Calculation Period: 2008-09-01 -> 2009-0930)
YEAR
Jan
2008
2009
Mean of
monthly
Discharge
Feb
Mar
410
290
273
410
289
273
Apr
May
Jun
Jul
Aug
429
487
121
51.9
105
Sep
8.48
28.9
429
487
121
52
105
19
Oct Nov Dec
7.03 57.3 529
7
57
** Incomplete data have been used for statistical calculation
Table 2. Discharge data for the West Fork of the Greenbrier in cubic feet per second. Taken from USGS
gauging station 03180500, Greenbrier River at Durbin, WV.
26
529
Figure 1. Location of study site along the West Fork of the Greenbrier River, Pocahontas County, West
Virginia. Study reach is located between the two red lines.
27
Figure 2. Diagram of study reach. Flags were placed every 20 m to aid in documenting hellbender
capture locations.
28
Figure 3. Photo of diurnal rock-lifting survey technique. Photo by George Grall.
29
Figure 4. Measuring apparatus and a recently captured hellbender. Photo by David Fields.
30
Figure 5. Hellbender at night with only head exposed. Note the scarring near the mouth. Photo by Doug
Horchler.
31
Figure 6. Marking Technique. Insertion of a P.I.T. tag into the fatty dorsal region of the tail. Photo by
Casey Bartkus.
32
Figure 7. Documented evidence of reproduction within study reach in 2009. Note both a nest site and a
potential parental care event.
33
Figure 8. A loose hellbender egg found protruding from a nest in the West Fork of the Greenbrier on
September 5th, 2009. Note how the embryo is beginning to cleave. Photos by Doug Horchler.
34
1998-2009 Recaptures Δ Mass (g)
250
200
Eleven-year change in mass (g)
150
100
50
0
1
2
3
4
5
6
7
8
9
10
11
-50
-100
-150
-200
-250
Figure 9. Change in mass (g) of the eleven 1998 recaptured hellbenders from the West Fork Greenbrier.
35
Figure 10. Hellbender # 985120027944372 was the smallest hellbender (23 cm T.L., 79 g) captured
during the study. Photo by Jeff Humphries.
36
Number Captured
Size Histogram of Hellbenders from 1998 (N = 37)
14
M
12
F
10
8
6
4
2
0
25-30
30-35
35-40
40-45
45-50
50-55
55-60
Size Classes (TL in cm)
Figure 11. Demographics for the 1998 West Fork of the Greenbrier hellbender population. Note the
almost even sex ratio (1.06:1), and a normal size class distribution for each sex.
37
Size Histogram of Hellbenders from 2009 (N = 37)
14
M
Number Captured
12
F
10
8
6
4
2
0
25-30
30-35
35-40
40-45
45-50
50-55
55-60
Size Classes (TL in cm)
Figure 12. Demographics for the 2009 West Fork of the Greenbrier hellbender population. Note the sex
shift to a male dominated population (2.1:1), and shift toward larger size classes of hellbenders.
38
1998-2009 West Fork Hellbender Growth
6.00
y = 108.14e-0.083x
R² = 0.4065
Growth through 2009 (cm)
5.00
4.00
3.00
2.00
1.00
0.00
35
40
45
50
55
60
Total Length (cm) in 1998
Figure 13. Eleven-year growth curve for 1998 hellbenders recaptured in 2009 (n=11) on the West Fork
of the Greenbrier. Average 11 year growth was 3.38 cm (range= 0.6-5.2 cm).
39
Figure 14 . Mudpuppy (Necturus maculosus) found August 11th, 2009 underneath large rock. Total length
was 9.2 cm. Photo by Geoge Grall.
40
Figure 15. Hellbender #0A0008347. Captured on the West Fork of the Greenbrier in May 2009. Note
the missing feet on both front left and rear left legs. Photo by George Grall.
41
Figure 16. Hellbender #008-866-349. This hellbender had a broken left shoulder and a large gash under
his left front leg, significant scarring on his head and body, and in very poor and weakened condition
when recaptured in 2009. He had lost over 35% of his body mass from 1998 (-225 g). Lower left photo by
Scott Jones, other three photos by Kevin Messenger.
42
Male Hellbender (# 0A00081134) Δ Mass (g)
640
620
620
600
Mass (g)
580
570
560
540
540
525
520
500
480
460
5/1/09
6/1/09
7/1/09
8/1/09
9/1/09
Date
Figure 17. Hellbender (#0A00081134), a male, showed a steady decline in mass from his initial capture
on May 24th, 2009. This loss of approximately 15% of his body mass likely represents stress in
preparation for the breeding season.
43
Figure 18. Male hellbender (#0A00081134) captured on September 7th, 2009. Note the very swollen
cloaca and the emission of milt upon being handled. Photo by Doug Horchler.
44
Figure 19. An example of polydactylism. This female hellbender had nine toes on her rear right foot.
Photo by Doug Horchler.
45
Figure 20. Dead hellbender discovered September 5th, 2009 upstream from the study site. Note that this
hellbender is a male and has a very swollen cloaca. Cause of death is unknown. Photos by Doug Horchler.
46
West Fork Crayfish Survey
Fish
6%
Both Crayfish and
Fish
3%
No Crayfish
48%
Crayfish
43%
Figure 21. Results of August 2009 crayfish survey. I noted the presence/absence of crayfish under
100 rocks greater than 30 cm wide chosen at random. More than half of the rocks surveyed had
either crayfish and/or fish present underneath them.
47
Figure 22. The New River Crayfish, Cambarus (Hiaticambarus) chasmodactylus. This species of
crayfish is the likely the staple prey item for hellbenders in the West Fork of the Greenbrier.
Photo by Kevin Messenger.
48